Melatonin, sleep disturbance and cancer risk

Laboratory of Chrono-Neuroendocrine Oncology, Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
Sleep Medicine Reviews (Impact Factor: 8.51). 08/2009; 13(4):257-64. DOI: 10.1016/j.smrv.2008.07.007
Source: PubMed


The pineal hormone melatonin is involved in the circadian regulation and facilitation of sleep, the inhibition of cancer development and growth, and the enhancement of immune function. Individuals, such as night shift workers, who are exposed to light at night on a regular basis experience biological rhythm (i.e., circadian) disruption including circadian phase shifts, nocturnal melatonin suppression, and sleep disturbances. Additionally, these individuals are not only immune suppressed, but they are also at an increased risk of developing a number of different types of cancer. There is a reciprocal interaction and regulation between sleep and the immune system quite independent of melatonin. Sleep disturbances can lead to immune suppression and a shift to the predominance in cancer-stimulatory cytokines. Some studies suggest that a shortened duration of nocturnal sleep is associated with a higher risk of breast cancer development. The relative individual contributions of sleep disturbance, circadian disruption due to light at night exposure, and related impairments of melatonin production and immune function to the initiation and promotion of cancer in high-risk individuals such as night shift workers are unknown. The mutual reinforcement of interacting circadian rhythms of melatonin production, the sleep/wake cycle and immune function may indicate a new role for undisturbed, high quality sleep, and perhaps even more importantly, uninterrupted darkness, as a previously unappreciated endogenous mechanism of cancer prevention.

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Available from: David E Blask, Oct 02, 2014
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    Journal of Clinical Nursing 09/2015; DOI:10.1111/jocn.12985 · 1.26 Impact Factor
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    Animal Behaviour 03/2015; 101. DOI:10.1016/j.anbehav.2014.12.001 · 3.14 Impact Factor
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    Sleep Medicine 12/2014; 16(2). DOI:10.1016/j.sleep.2014.12.004 · 3.15 Impact Factor
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